Aminonaphthyl and alkylaminonaphthyl n-methylcarbamates and insecticidal compositions thereof



United States Patent 3,275,507 AMINONAPHTHYL AND ONAPH- THYL N-METHYLCARBAMATES AND INSEC- TICIDAL COMPOSITIONS THEREOF John R. Kilsheimer, South Charleston, W. Va., and Herbert H. Moorefield, Raleigh, N.C., assignors to Union Carbide Corporation, a corporation of New York No Drawing. Original application Dec. 30, 1960, Ser. No. 79,522, now Patent No. 3,236,877, dated June 9, 1964. Divided and this application Oct. 7, 1965, Ser.

15 Claims. (Cl. 167-32) XHcI wherein X is an integer having a value of O or I and R and R are selected from the group consisting of hydrogen, lower alkyl and alkaryl radicals wherein said R and R can be the same or different. Examples of such com pounds include I-(S-aminonaphthyl) N-methylcarbamate,

1-(S-N,N'-dimethylaminonaphythl N-methylcarbamate, 1-(S-N',N-diethylaminonaphythyl) N-methylcarbamate, 1(5-N',N-di-n-propylaminonaphthyl) N-methylcarbamate, 1-(5-N',N-di-isopropylaminonaphthyl) (N-methylcarbamate, the l-(5-N,N'-dibutylaminonaphthyl) N-methylcarbamates, the 1-(S-N,N'-dipentylaminonaphthyl) N-methylcarbamates, the 1-(5-N',N-dihexylaminonaphthyl) N-methylcarbamates, the l-(5-N',N-diheptylaminonaphthyl) N-methylcarbamates, the 1-(5-N,N-dioctylaminonaphthyl) N-methylcarbamates, l-(S-N'-methyl-N'-ethylaminonaphthyl) N-methylcarbamate, 1-(S-N-methyl-N'-propylaminonaphthyl) N methy1carbamate, 1-(S-N'-methyl-NT-pentylaminonaphthyl) N-methylcarbamate, 1-(5-N'-methyl-N'-hexylaminonaphthyl) N-mathylcarbamate, 1-(5-N'-ethyl-N-propylaminonaphthyl N-methylcarbamate, l-(5-N'-ethyl-N'-pentylaminonaphthy1) N-methylcarbamate, 1-(5-N-methyl-N'-benzylaminonaphthyl) N-methylcarbamate and the like. Particularly preferred are the compounds wherein R and R have up to about 7 carbon atoms.

The compounds of this invention can be prepared generally by reacting the appropriate substituted l-naphthol with phosgene in the presence of a base to form the corresponding chloroformate. The chloroformate is then reacted with monomethylamine to form the substituted l-naphthyl N-methylcarbamate. This synthesis can be graphically represented by the following equations:

Step A:

Step A can be conducted at a temperature of from about 30 C. to about 175 C. The reaction can be initiated by adding phosgene dissolved in toluene, benzene, or other suitable organic solvent, to an aqueous solution of the substituted naphthol and a base, preferably sodium hydroxide. The reaction is generally exothermic so that some external cooling is usually necessary. This reaction can be conducted in the presence of basic compounds other than sodium hydroxide, such as pyridine and dimethylaniline, to facilitate removal of hydrogen chloride as an organic hydrochloride. In these cases the reaction can be advantageously conducted in anhydrous solvents, such as toluene, dioxane and the like.

Step B can be conducted at a temperature of from about ---30 C. to about C. The chloroformate can be added to a solution of methylamine in a solvent such as water, benzene, hexane, dioxane and toluene.

When the products are crystalline solids they can be separated from the reaction mixture by filtration or centrifugation and dried. In other cases the solvent is removed by distillation and the product is taken as a residue.

An alternate procedure for the'preparation of the compounds of this invention is by the reaction of the appropriate substituted l-naphthol with methyl isocyanate, as represented by the following schematic equation:

+ O aNOO R-N-R RI IR' This reaction is conducted by reacting the appropriate naphthol with methyl isocyanate in the presence of an anhydrous, inert solvent and a catalyst in a pressure vessel under autogenous pressure and at from about ambient temperatures to about 200 0. The solvent is distilled oil" from the reaction mixture, leaving as a residue, the methylcarbamate. The catalyst can be an organo-rnetallic compound such as dibutyl tin diacetate-or an organic tertiary amine such as pyridine. Applicable reaction solvents are ethyl ether, benzene, methanol, and mixtures thereof. When R and R are hydrogen this process must be modified. The amine group is first blocked with a filtrate were added 200 milliliters of a mixture of equal EXAMPLE I 1-(5-aminonaphthyl) N-methylcarbamate o c oNHorn A mixture containing 121 grams of S-acetamido-lnaphthol, 3 grams. of dibutyl tin diacetate, and 500 milliliters of dioxane was charged to a reaction vesseland heated to C., after which 31.3 grams of methyl i'socyanate were added to the reaction mixture over a period of minutes. The resulting mixture was held at 25 C. with agitation for three days, after which the dioxane was distilled 01f. The solid residue remaining in the reaction vessel was heated with methanol to the .boiling point and then cooled to C. The crystals of 1-(5- acetamidonaphthyl) N-methylcarbamate that formed upon cooling were filtered from the alcohol and dried.

A mixture containing 25.8 grams of I-(S-acetamidonaphthyl) N-methylcarbamate, 20 grams of concentrated hydrochloric acid, and 1(l0millilitersv of acetic acidwas charged toga reaction vessel and'heated at the boiling point (approximately 100 C.) for 2.5 hours. The a 1 mixture was then cooled to 25 C. and filtered. To the parts by volume of ethyl ether and petroleumvether. An insoluble oil phase wasformed. The water. and ether phases were discarded and acetone was added to .the insoluble oil layer. The solid that formed was filtered from the mixture and air dried. The solid is 1-(5-aminonaphthyl) N-methylcarbamate hydrochloride which has a melting point of 225 C. and analyzed as follows: N,

10.7%; C1, 13.4%; (calculated N, 11.1%; C1, 14.0%).

A portion ofthe dry solid was dissolved in water and the resulting solution was neutralized with sodium bicarbonate, whereby I-(S-aminonaphthyl) N-methylcarbamate. precipitated. The. carbamate crystals were filtered out of the mixture, washed with water, and then with ethyl ether,- and air dried. The crystals thus recovered melted at 124 C. andanalyzed as follows: C, 68.1%;

H, 5.9%; N, 11.5% (calculated: C, 66.6%; H,5.7%;

N, 13.0%). The desired 1-(5-aminonaphthyl) N-methylcarbamate contains a small amount of S-amino-l-naphtholformed during the sodium bicarbonate neutralization step.

EXAMPLE 11 1 (5 -N ',N '-dimethyaminonaphthyl N-methylcarbamate O C ON HCH;

A mixture containing 40' grams of 5-N,N-dimethyl- I amino-l-naphthol, 13 grams of methyl is'ocyauate, 5 drops (approximately 0.3 cc.) of pyridine and ,100 milliliters of of anhydrous benzene was charged to a pressure vessel' and was held at ambient temperature and under autogenous pressure for four days. The resulting reaction mixture was removed from the pressure vessel and distilled to remove the benzene. The solids residue thatremained was recrystallized from xylene and dried. The 1-(5- N',N'-dimethylaminonaphthyl) N-methylcarbamate thus produced weighed 241 grams, melted at 133 C. andanalyzed as follows: N',.11.3 percent (calculated: N, 11.5

percent).

, I EXAMPLE III p 1-(5-N',N'-diethylaminon'aphthyl) N-methylcarbamate OOONHCH;

C2Hs- T.-C2 s" A mixture of 50 grams'of 5-N,N=diethylamino-1-naph thol, 20 grams of methylisocyanate, 5 drops (approximately 0.3 cc.) of pyridine, and .100 milliliters of ethyl other was charged to a pressure vessel and was held at ambient temperature and autogenous pressures for four days.

The resulting reaction mixture was removed from the pressure vessel and ethyl ether was removed by distillation. The solid residue that remained was 1-(5-N',N?-

, diethylaminonaphthyl) N-methylcarbamate and weighed 62 grams, which analyzed as follows: .N, 10.1 percent (calculated: N, 10.3 percent).

EXAMPLEIV I-(5-N'-methyl-Ni-ethylaminonaphthyl) N-methylcarbamate Employing the procedure .of, Example III',=I 1-(5-N'- methyl-N ethylaminonaphthyl) N- methylcarbamate is prepared by the reaction, of 5- (N-methyl-N-ethylamino)- l-naphthol and methyl isocyanate in the presence of pyri-r dine and ethyl ether.

The compounds of the instant invention are useful as, insecticides. They are particularly effective as :insec-" ticides against Mexicanbeanbeetles and beanaphids:

as is demonstrated by the following tests;

The compoundsofthe instant invention are reported in the below-described .testsas follows:

Compound No.: Compound I I-(S-amirionaphthyl), N-methylcarbamate. II 1-(5-N',N'-- dimethylaminonaphthyl); N'methylcarbamate. F III 1-(5 N',N' diethylaminonaphthyl V N-methylcarbamate.

IV I-(S-aminonaphthyl). N-methylcarbamate hydrochloridesolution.

to give the desired concentration of toxicant. The solu+,

tions containing various concentrations in a dilution series a were then tested on Mexican bean beetle larvae and bean aphids. Percent mortality of the test insects was plotted against the toxicant concentration on logarithmic ,probability paper. The concentration inmilligrams of'toxi-: cant .per 100 milliliters of solution needed for 50 percent mortality (LD5g value) was interpolated from a line drawn through the points so plotted. I

MEXICAN BEAN BEETLE LEAF-DIP TEST The test insects were fourth instar larvae of the Merxi-i can bean beetle (Epilachna varivestis Muls.),,that had been reared on tende'rgr een beans, at a temperature of F. :5 F. and a relative humidity of 50 percent :5 percent. Four randomly selected larvae were placed in" a 9-cm Petri dish lined with filter paper and containing -a leaf of a Tendergreen bean plant. The leaves were prepared by excising paired seed leaves from thebean plants and dipping the excised leaves in the test solutions prepared according to the above directions until thoroughly wetted. Excess liquid was removed from the surface of the leaf by gentle shaking. The leaves were then dried in a ventilated hood. Wilting of the leaves during drying was prevented by placing the leaf stems in. water. The dried, paired leaves were then separated and a single leaf was placed in each Petri dish. After placing the leaf and larvae in the Petri dishes, the dishes were closed, labeled, and heated at 80i5 F. for three days. Although the larvae could easily consume the whole leaf within twentyfour to forty-eight hours, no additional leaves were added. Larvae exposed to untreated leaves remained vigorous during the entire holding period and did not advance to the quiescent prepupal state. Larvae which were unable to move the length of the body, even upon prodding, were considered dead.

APHID FOLIAGE SPRAY TEST The test insects were adult and nymph stage bean containing the compounds of this invention is to first prepare a liquid concentrate containing such compounds by dissolving said compound in a solvent such as acetone, toluene, xylene or kerosene. This liquid concentrate can then be added to water together with suitable surface active dispersing agents whereby the compounds of the instant invention are dispersed in the water.

A third method of preparing liquid compositions containing the instant compounds is to prepare a wettable aphids (Aphis fabae Scop.) reared on potted dwarf nasturtium plants at a temperature of 65 to 70 F. and a relative humidity of 50 to 70 percent. The aphid populations in the pots were reduced to 100 to 150 individuals per pot by trimming off plants containing excess aphids. The pots were sprayed with toxicant solution, employing a DeVilbiss spray gun at forty pounds pressure, for thirty seconds, in which time 100 to 110 milliliters of the test solution, an amount sufficient to wet the plants to run-off, was applied. A control solution consisting of 100 to 110 milliliters of an aqueous solution of acetone and wetting agent was also sprayed on infested plants. After spraying, the pots were placed on their sides on a sheet of white paper that had been previously ruled into squares to facilitate counting, and held for twenty-four hours at a temperature of 80 F. :5" F. and a relative humidity of 50 percent i5 percent. Aphids that had fallen to the paper and were unable to remain standing after being uprighted and those remaining on the plants that could not move the length of the body, even upon prodding, were considered dead.

The results of the abovedescribed tests are summarized in Table I below.

From Table I it can be seen that the compounds of the instant invention are useful as insecticides and are very effective when employed against Mexican bean beetles or bean aphids. The compounds of the instant invention are also insecticidally active toward the Southern armyworm and house flies. Furthermore, they are stable in the presence of light and air.

The compounds of the instant invention can be applied to plants or other areas to be protected by contacting such area with a compound of the instant invention in an undiluted form, as a dust when admixed with finely powdered inert carriers, or in a liquid form. The rate of application can vary from about 0.5 to about 5 pounds of the compound per acre.

When the compounds of the instant invention are applied as dusts they can be mixed with suitable particulate extenders, such as clay, chalk, talc, diatomaceous earth, pyrophyllite, infusorial earth, fullers earth, pumice, bentonite, and flours, such as cotton seed flour and walnut shell flour.

powder by dispersing said compounds on or in a finely divided inert solid such as clay, chalk, talc, bentonite, fullers earth and the like. These compositions may also contain dispersing or wetting agents as desired. These compositions can then be mixed with water to provide a liquid insecticide suitable for application to the areas to be treated.

The surface active agents that can be employed in the above-described compositions can be any of the known anionic, cationic and non-ionic wetting, emulsifying and dispersing agents, such as aralkyl, polyether alcohols, aralkyl polyether .sulfonates, aralkyl polyether sulfates, quaternary ammonium compounds, and the like. When these surface active agents are employed they generally comprise from about 0.5% to about 5% by weight of the total composition.

We claim:

1. An insecticidal composition comprising a compound having the structural formula:

I RN-R x Her wherein X is an integer having a value of from 0 to 1, R and R are selected from the group consisting of hydrogen, lower alkyl and alkaryl radicals and said R and R may be the same or different, and a carrier therefor.

2. An insecticidal composition comprising l-(S-aminonaphthyl) N-methylcarbamate and a carrier therefor.

3. An insecticidal composition comprising l-(5-N',N- dimethylaminonaphthyl) N-methylcarbamate and a carrier therefor.

4. An insecticidal composition comprising l-(5-N,N'- dimethylaminonaphthyl) N-methylcarbamate and a carrier therefor.

5. An insecticidal composition comprising 1-(5-aminonaphthyl) N-methylcarbamate hydrochloride and a carrier therefor.

6. The process for killing insects which comprises applying an insecticidal amount of a compound having the structural formula:

?CONHCH3 R may be the same or diflferent, to a locus to be protected.

7. The process for killing insects which comprises applying an insecticidal amount of I-(S-aminonaphthyl) N-methylcarbamate to a locus to be protected.

8. The process for killing insects which comprises applying an insecticidalamount of 1-(5-,N",Nvdimethyl aminonaphthyl) N-methylcar-bamate to a locus to beprotected.

9. The .process for killing insects which comprises applying an insecticidal amount of 1-(5-N' ,N-d.iethyl aminonaphthyl) N-methylcarbamate to a locus to be pro tected.

10. The process for killing insects which comprises applying an insecticidal amount of I-(S-aminonaphthyl) N-methylcarbamate hydrochloride to a locus to be pro-' tected.

11. The process for killing insects. which comprises applying an insecticidal amount of a compound having the formula: 1

( DCONHCH,

wherein X is an integer havingla value of from O to 1, R and R are selected from the group consisting of hydrogen, lower alkyl' and alkaryl radicals and said R1 andyR' can be the same or difieren-Lito. said insects.

y 12. The process for :killing insects which comprises applying an insecticidalamount of I-(S-aminonaphthyl) N-rnethylcarbamate to said insects.

13. The process for killing insects which comprises applying an insecticidal amount o f 1-(5-N,N'-dimethylaminonaphthyl) N-methylcarbamate to said insects. V

14. The process for .killing insects which comprises; applying an insecticidal. amount of .1-(5-N,N-diethylf aminonaphthyl) N-methylcarbamate to said insects.

15. The process for killing insects, which comprises Q applying an insecticidal amount of I-(S-aminonaphthyl) N-methylcarbamate hydrochloride; to said insects.

References Cited by the Examiner JULIAN S. LEVITT, Primary Examiner.

G. A. MENTIS, Assistant Examiner. 

6. THE PROCESS FOR KILLING INSECTS WHICH COMPRISES APPLYING AN INSECTICIDAL AMOUNT OF A COMPOUND HAVING THE STRUCTURAL FORMULA: 